Comminution of single real waste particles in a swing-hammer shredder and axial gap rotary shear

Abstract

Comminution plays an essential role in waste preparation. Most wastes can be classified as non-brittle and heterogeneous materials. The breakage behavior of the components and the individual particles strongly influences the comminution of such materials, so it is necessary to understand each component's breakage behavior under different stresses to develop heterogeneous materials' comminution. Therefore, single-particle comminution tests of real wastes– PET bottle, cardboard, textile, detergent (HDPE) bottle- in a swing-hammer shredder and axial gap rotary shear were carried out. The breakage probability was used to describe the effect of the stress type and stress velocity on the different material types. The applicability of the results in the shredders' operation and design was introduced. In swing-hammer shredder, the PET, HDPE, and textile are complicated, while cardboard is easy to break. The rotor velocity has a strong influence on the breakage probability of all three materials in the hammer shredder; the higher the velocity, the lower the stress number for a certain breakage probability, while in the axial gap rotary shear, no clear correlation was observed.